Chapter One: Suzie, Do You Copy? - S3-E1
Factual error: When Dustin's toy collection "comes to life" (thanks to Eleven), one of the robots is the Transformer Ultra Magnus. Though it appears to be modified with a motorized engine that the actual toy didn't have, that's not the mistake, as there no reason Dustin couldn't have modified it. The error is that the season is set in July 1985, but Ultra Magnus wasn't released in the U.S. until 1986. (Yes, the toy was available as a Diaclone in Japan, but in a different color scheme. Dustin's has the coloring of the U.S. version, and even if he somehow ended up with the Diaclone version, it's highly unlikely he would have repainted a Japanese toy to resemble a Transformer he wouldn't know about the existence of yet, as the 'Transformers' animated movie wasn't released until August 1986).
Answer: Technically Steve was never intended to die in Stranger Things. The Duffer brothers wrote a pilot script for a miniseries called Montauk that would eventually become Stranger Things. In that version of the story Steve is a more overtly villainous character and is killed by a monster. The Steve character was reworked once Stranger Things was created due to Joe Keery's more likeable approach to the character.
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